Vibrating filament lamp with auxiliary stationary filament

ABSTRACT

An incandescent lamp with a vibrating filament in which a secondary, stationary, element, such as a filament is used to produce additional light and/or also to select and adjust the electrical operating characteristics of the lamp.

14 1 June 10, 1975 VIBRATING FILAMENT LAMP WITH 315/267 315/267 Kaufman et a1. 313/160 X 3 548 255 12/1970 3,549,946 12/1970 Kyp 3 790,998 11/1971 AUXILIARY STATIONARY FILAMENT [75] Inventors: Wolfgang E. Thouret, Verona, NJ:

Rudolph Kaufman, Bronxville, N.Y.

Duro-Test Corporation, North Bergen, NJ.

Primary Examiner-R. V. Rolinec Assistant Examiner-E R. LaRoche [73] Assignee:

Attorney, Agent, or Firm-Darby & Darby [22] Filed: Sept. 27, 1974 Appl. No.: 509,831

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3,237,053 315/267 10 Claims, 5 Drawing Figures VIBRATING FILAMENT LAMP WITH AUXILIARY STATIONARY FILAMENT Decorative incandescent lamp with vibrating filaments that simulate the flickering movements of a candle flame are known in the art and are commercially available. Lamps of this type have a filament of a relatively thin and flexible material. such as carbon. which is formed in a loop of a desired shape. A permanent magnet is mounted either inside the glass lamp bulb or on the outside of the bulb with its magnetic field of a proper strength and oriented to react with the alternating current flowing through the filament to cause the filament to vibrate. The alternating current applied to the filament is also of a magnitude to make it incandesce and thereby produce the impression of a flickering live flame or for the purpose of esthetic appeal. Lamps of this general type are disclosed in US. Pat. Nos. 3,237,053, 3,548,255, 3,549,946, 3,790,998 and French Pat. No. 368,913.

In decorative lamps of this type, the amount of light produced by the vibrating filament is usually relatively small. This is due to the fact that the requirement of maintaining rapid vibration of the filament, sometimes vibration of a relatively large amplitude for a long period of use, necessitates the use of a relatively thin filament with particular elastic properties. These elastic properties can generally be maintained only if the operating temperature of the filament is kept very low, for example under I,600C. At such low temperatures, the luminous efficacy of most, if not all, conventional filament materials that can be used is very small, often well under 3 lumens per watt. Consequently, while they are useful for generating decorative effects, vibrating filament lamps have only limited utility as light sources for illumination.

In addition, when designing a vibrating filament lamp for a relatively high voltage operation, for example 220 or 230 volts, and at a lower frequency of alternating current than that found in the United States, for example O hertz instead of 60 60 hertz, the elastic properties of the filament needed to cause vibration are such as to operate against the construction of such a lamp. That is, for example, at a higher operating voltage the resistance of the lamp filament would have to beincreased to obtain the same lamp current produced at a lower operating voltage. To do this the filament would have to be made of smaller diameter. This would further weaken its needed elastic properties over long periods of use.

The present invention provides a new type of vibrating filament lamp that can fulfill one or both requirements of producing additional light and permitting the electrical properties of the vibrating filament to be adjusted. In accordance with the invention, the lamp utilizes both a vibrating filament and a secondary resistive element, which can be another filament, within the same glass bulb, the secondary element preferably being stationary. The vibrating filament lamps of the present invention fulfill two major requirements. First, they produce esthetically pleasing decorative effects through the use of a vibrating filament. In addition, the stationary element, when it is a secondary filament, can produce a substantial additional light output as re quired. The secondary element, when either a filament or a resistor, which can be connected electrically either in series or in parallel with the vibrating filament, permits the electrical characteristics of the lamp to be adjusted and more readily controlled. By separating the light producing and decorative producing functions between two different filaments the most suitable materials, operating temperatures and dimensions can be used for each.

It is therefore an object of the present invention to provide a vibrating filament lamp utilizing a secondary resistive element.

A further object is to provide a vibrating filament lamp utilizing a secondary filament to produce additional light.

Another object is to provide a vibrating filament lamp using a secondary filament which is connected to adjust the electrical operating characteristics of the lamp.

Still a further object is to provide vibrating filament lamp having a secondary resistive element used to adjust the electrical operating characteristics of the lamp.

An additional object is to provide a vibrating filament lamp having a secondary, stationary, filament electrically connected to the operating filament.

Other objects and advantages of the present invention will become more apparent upon reference to the following specification and annexed drawings, in which:

FIG. 1 is an elevational view of one form of lamp, a portion of which has been broken away;

FIG. 2 is an elevational view ofa second embodiment of the lamp according to the present invention, also with a portion broken away;

FIG. 2A is a top view of the lamp of FIG. 2',

FIG. 3 is an elevational view, partly broken away, of a further embodiment of the lamp; and

FIG. 4 is an elevational view of another embodiment of lamp, partly broken away, in which the secondary element is connected in parallel.

Referring to FIG. 1, a conventional bulb 10 of ordinary soft glass, is shown having the usual standard base 12 with its electrical terminals on the threaded base 13 and the insulated base button 14. A stem 16 is sealed into the base 12 and includes an exhaust tubulation 17 which is sealed or tipped off. A pair of lead wires 18 and 19 extend through the stem 16 and are electrically connected to the base terminals 13 and 14.

A filament 20 formed as a loop of a desired suitable shape is provided. The loop need not be entirely in the same plane. Filament 20 is of a material having the necessary elastic properties to vibrate. Such filaments can be made, for example, of carbon which is aged in a particular manner. Reference is made to the aforegoing patents for a more complete disclosure of the filament which, in itself, forms no part of the subject invention. A permanent magnet 22 is held at one end' of a rod 23 whose other end is mounted to an extending button 25 of glass or other suitable insulating material located on top of stem 16. The magnet 22 can be held to the rod by an adhesive, spot welding, or any other suitable means. The permanent magnet 22 can be of any suitable material, for example, Alnico. Its field strength is selected and its orientation is such, with respect to filament 20, so as to interact with the alternating current flowing through the filament 20 to produce vibration thereof.

A secondary element, in the form of a filament 26, is provided. Secondary filament 26 is here shown as a singly coiled filament, for example of tungsten wire, and is similar to filaments used in ordinary incandescent lamps for general lighting purposes. The secondary filament 26 is held in loops 27 on the ends of each of four or five mounting wires 28 which extend from the button 25.

A series electrical connection is provided by having one end of vibrating filament connected to lead wire 18 at point 34. The connection can be made by welding, clamping, etc. The stem 16 also carries a wire insert 31, of nickle, molybdenum or other suitable material which is bent at a right angle to form a hook 33. One end of the secondary filament 26 and the other end of the vibrating filament 20 are clamped together with hook 33 to form an electrical connection. The other end of the secondary filament 26 is connected to the lead wire 19.

When alternating current is applied to the base terminals 13, 14 of the lamp, it passes through the series combination of the two filaments 20 and 26. Secondary filament 26 is stationary and incandeses to produce light. A voltage drop occurs across the secondary filament. The alternating current passing through the filament 20 interacts with the magnetic field produced by magnet 22 to cause the filament to vibrate back and forth out of its normal position, that is, when it is at rest.

A lamp according to FIG. 1 can be made to operate at relatively high voltages. A satisfactory lamp for operation at 240 volts and at 50-60 Hz has been constructed with the following electrical data:

supply voltage 240 volts voltage drop on vibrating (carbon) filament 165 volts voltage drop on secondary (tungsten) filament 75 volts lamp current I25 milliamperes total lamp wattage 29 watts.

As seen, the lamp of FIG. 1 produces a considerable amount of light output across the secondary filament which drops 75 volts. Also, the drop of 75 volts across the secondary filament leaves only 165 volts across the vibrating filament 20 which means that a fairly thin filament with good elastic properties can be used to produce the vibration.

FIGS. 2 and 2A show a further embodiment wherein the secondary element is also a non-movable filament. Similar reference numerals are used for this embodiment as in the embodiment of FIG. 1. Here, the secondary filament 38 is a short, doubly coiled tungsten filament similar to those found in ordinary incandescent lamp bulbs. In this case, the rod 23 for holding magnet 22 is electrically connected directly to the lead wire 19.

The mounting wire 31 on the stem 16 is bent at a right angle at its upper end. One end of the coiled coil secondary filament 38 and one end of the vibrating filament 20 are clamped together by the book 33 at the end of wire 31 to form an electrical connection. The other end of the secondary filament 38 is electrically connected to the lead wire 19 through the rod 23. A series circuit is completed by connecting the other end of the vibrating filament to the lead wire 18 at point 34.

As in the case of the lamp of FIG. 1, in FIG. 2, the secondary filament is connected in series with the vibrating filament. The operation of the lamp is as previously described. Typical electrical operating characteristics for a lamp of this type are similar to that described above with respect to the lamp of FIG. 1.

FIG. 3 shows a further embodiment of the invention wherein the light output of the secondary element is of lesser importance and the electrical properties of the secondary element are selected primarily to adjust the total electrical characteristics of the lamp.

Here, an annular shaped electrical resistor 40 is provided which has the required electrical resistance value and does not give any appreciable light output. The general construction of this lamp is similar to that shown in FIGS. 1 and 2. The bulb, base, stem, magnet and vibrating filament are arranged similarly and have the same reference numerals. The resistor 40 fits over the stem and is either press fit or held thereto by an adhesive. Resistor 40 has two leads 41 and 42.

The electrical circuit is a series connection. Lead wire 19 is connected to rod 23 and the resistor lead 41 is also connected thereto. The other resistor lead 42 is connected, such as by spot welding, to wire 31 and one end of the vibrating filament 20 is connected to the wire book 33. The other end of filament 20 is connected to lead 18 at point 34. The operation of the lamp of FIG. 3 is as described previously.

A lamp of the type shown in FIG. 3 has been constructed with the following electrical operating characteristics: I

supply voltage 220 volts voltage drop on vibrating filament 20 volts lamp current I25 milliamperes resistance of series resistor 40 600 ohms wattage consumed in series resistor 9.4 watts total lamp wattage 27.5 watts.

The value of resistor 40 can be selected to produce the required voltage drop on filament 20.

FIG. 4 shows a lamp with parallel electrical connection for the secondary element. Here, a filament 45 is used which is shown as the coiled coil type. The ends of the filament 45 are connected to two mounting wires 21a and 2112 which are in turn connected to the lead wires 18 and 19. The ends of the vibrating filament 20 are also connected to the lead wires. In this embodiment secondary filament 45 acts as a light source and also adjusts the operating characteristic of the vibrating filament 20. A resistor which does not emit light can be substituted for the parallel connected filament 45.

As should be apparent, the lamps of the invention provide several advantages. Where a filament is used as the secondary element, it supplies a second, steadily burning, brighter light source that supplements the decorative flame-light lighting effect generated by the vibrating primary filament. The secondary filament can have an additional useful, and in some cases necessary, function in that it can assist in adjusting the electrical characteristics of the lamp to the requirements of the main supply voltage under conditions when the material properties and the dimensions of the vibratory filament cannot be chosen to match the supply voltage without seriously impairing the ability of this filament to vibrate properly and continuously over the required long life of the lamp.

In those cases where the light producing function of the secondary element is not essential, its function as an adjusting element for the lamps electrical characteristics serves as its main purpose. In such cases, the secondary element can be designed to operate at a very low temperature where it remains relatively dark and its main function becomes that of a resistor with the proper ohmic value that is required for giving the entire lamp certain desired electrical characteristics. Such characteristic values may be a stipulated wattage input or a stipulated operating current at a given supply voltage when these properties cannot be obtained solely by adjusting the dimensions and material properties of the vibrating filament without seriously impairing its ability to oscillate as desired.

While the preferred embodiments of lamps have been described with the magnet mounted internally of the envolope, it should be understood that the magnet can be located on the outside of the envelope.

What is claimed is:

1. An incandescent lamp for operation from a source of alternating current comprising:

a transparent envelope,

means for producing a magnetic field,

a first filament, means for supplying the alternatin current to said first filament to cause said first filament to incandesce, means for mounting said first filament at a predetermined orientation with respect to said magnetic field to produce an interaction between said magnetic field and the current flowing through said first filament to cause said first filament to vibrate,

and second means having electrical resistance properties electrically connected to said first filament to produce a voltage drop across said second means.

2. An incandescent lamp as in claim 1 wherein said second means is electrically connected in series with said first filament.

3. An incandescent lamp as in claim 1 wherein said second means is electrically connected in parallel with said first filament.

4. An incandescent lamp as in claim 1 wherein said second means comprises a second incandescent filament, and means for mounting said second filament in a stationary position.

5. An incandescent lamp as in claim 4 wherein said second filament is electrically connected in series with said first filament.

6. An incandescent lamp as in claim 4 wherein said second filament is electrically connected in parallel with said first filament.

7. An incandescent lamp as in claim 4 wherein said envelope includes an internal stem to which is attached said means for supplying the alternating current to the first filament, and support means on said stem for holding said second filament.

8. An incandescent lamp as in claim 4 wherein said envelope includes an internal stem, a rod held by said stern and said rod holding the means for producing the magnetic field, said rod comprising a part of said means for supplying the alternating current to the first filament.

9. An incandescent lamp as in claim 1 wherein said second means comprises a resistor means.

10. An incandescent lamp as in claim 9 wherein said envelope includes an internal stem, said resistor means being mounted around said stem. 

1. An incandescent lamp for operation from a source of alternating current comprising: a transparent envelope, means for producing a magnetic field, a first filament, means for supplying the alternating current to said first filament to cause said first filament to incandesce, means for mounting said first filament at a predetermined orientation with respect to said magnetic field to produce an interaction between said magnetic field and the current flowing through said first filament to cause said first filament to vibrate, and second means having electrical resistance properties electrically connected to said first filament to produce a voltage drop across said second means.
 2. An incandescent lamp as in claim 1 wherein said second means is electrically connected in series with said first filament.
 3. An incandescent lamp as in claim 1 wherein said second means is electrically connected in parallel with said first filament.
 4. An incandescent lamp as in claim 1 wherein said second means comprises a second incandescent filament, and means for mounting said second filament in a stationary position.
 5. An incandescent lamp as in claim 4 wherein said second filament is electrically connected in series with said first filament.
 6. An incandescent lamp as in claim 4 wherein said second filament is electrically connected in parallel with said first filament.
 7. An incandescent lamp as in claim 4 wherein said envelope includes an internal stem to which is attached said means for supplying the alternating current to the first filament, and support means on said stem for holding said second filament.
 8. An incandescent lamp as in claim 4 wherein said envelope includes an internal stem, a rod held by said stem and said rod holding the means for producing the magnetic field, said rod comprising a part of said means for supplying the alternating current to the first filament.
 9. An incandescent lamp as in claim 1 wherein said second means comprises a resistor means.
 10. An incandescent lamp as in claim 9 wherein said envelope includes an internal stem, said resistor means being mounted around said stem. 